Tim Cook, a deaf, blind man, needed help communicating on his most recent flight from Boston to California, and unexpectedly ended up communicating and connecting with a 15-year-old girl who knows sign language.

The flight attendants made an announcement asking if anyone knew American Sign Language (ASL) so they could communicate with Cook. Clara Daly volunteered to help him as she has been studying ASL for the past year. Together Cook and Clara were able to communicate through finger spelling letters. Photos of the two communicating went viral on social media. A post from a passenger, Lynette Scribner, was shared over 500,000 times on Facebook.

Cook would hold onto Clara’s hands to feel the hand shape she was making as she spelled out her words.

Sign language is a common method of communication for deaf, blind people. Other forms of communication include braille, printing on the palm, tadoma, tactile fingerspelling, speech, speech reading, and tracking. According to the National Association of Regulatory Utility Commissions (NARUC), there are about 70,000-100,000 deaf, blind people living in the United States. Communication methods depend on the preference of the person.

Clara is not deaf, but began learning ASL to because it was the easiest language for her to learn with her learning disability. She is dyslexic and due to her dyslexia, reading and writing can be challenging. ASL is one language without these two components because it is a visual language.